/******************************************************
Row versions

(c) 1997 Innobase Oy

Created 2/6/1997 Heikki Tuuri
*******************************************************/

#ifndef row0vers_h
#define row0vers_h

#include "univ.i"
#include "data0data.h"
#include "dict0types.h"
#include "trx0types.h"
#include "que0types.h"
#include "rem0types.h"
#include "mtr0mtr.h"
#include "read0types.h"

/*********************************************************************
Finds out if an active transaction has inserted or modified a secondary
index record. NOTE: the kernel mutex is temporarily released in this
function! */

trx_t *row_vers_impl_x_locked_off_kernel(
    /*==============================*/
    /* out: NULL if committed, else the active
    transaction; NOTE that the kernel mutex is
    temporarily released! */
    rec_t *rec,            /* in: record in a secondary index */
    dict_index_t *index,   /* in: the secondary index */
    const ulint *offsets); /* in: rec_get_offsets(rec, index) */
/*********************************************************************
Finds out if we must preserve a delete marked earlier version of a clustered
index record, because it is >= the purge view. */

ibool row_vers_must_preserve_del_marked(
    /*==============================*/
    /* out: TRUE if earlier version should be preserved */
    dulint trx_id, /* in: transaction id in the version */
    mtr_t *mtr);   /* in: mtr holding the latch on the clustered index
                   record; it will also hold the latch on purge_view */
/*********************************************************************
Finds out if a version of the record, where the version >= the current
purge view, should have ientry as its secondary index entry. We check
if there is any not delete marked version of the record where the trx
id >= purge view, and the secondary index entry == ientry; exactly in
this case we return TRUE. */

ibool row_vers_old_has_index_entry(
    /*=========================*/
    /* out: TRUE if earlier version should have */
    ibool also_curr,     /* in: TRUE if also rec is included in the
                       versions to search; otherwise only versions
                       prior to it are searched */
    rec_t *rec,          /* in: record in the clustered index; the
                         caller must have a latch on the page */
    mtr_t *mtr,          /* in: mtr holding the latch on rec; it will
                         also hold the latch on purge_view */
    dict_index_t *index, /* in: the secondary index */
    dtuple_t *ientry);   /* in: the secondary index entry */
/*********************************************************************
Constructs the version of a clustered index record which a consistent
read should see. We assume that the trx id stored in rec is such that
the consistent read should not see rec in its present version. */

ulint row_vers_build_for_consistent_read(
    /*===============================*/
    /* out: DB_SUCCESS or DB_MISSING_HISTORY */
    rec_t *rec,               /* in: record in a clustered index; the
                              caller must have a latch on the page; this
                              latch locks the top of the stack of versions
                              of this records */
    mtr_t *mtr,               /* in: mtr holding the latch on rec; it will
                              also hold the latch on purge_view */
    dict_index_t *index,      /* in: the clustered index */
    ulint **offsets,          /* in/out: offsets returned by
                              rec_get_offsets(rec, index) */
    read_view_t *view,        /* in: the consistent read view */
    mem_heap_t **offset_heap, /* in/out: memory heap from which
                          the offsets are allocated */
    mem_heap_t *in_heap,      /* in: memory heap from which the memory for
                              old_vers is allocated; memory for possible
                              intermediate versions is allocated and freed
                              locally within the function */
    rec_t **old_vers);        /* out, own: old version, or NULL if the
                            record does not exist in the view, that is,
                            it was freshly inserted afterwards */

#ifndef UNIV_NONINL
#include "row0vers.ic"
#endif

#endif
